SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '782c72a36c6c064b558794cc27f0f5d28831df91eb7339196655d5589b1ce19f' 
  AND token = '1JdKVK4fqqJifvhdaV2dvrtJgrfFCasFv+Uwz6vU6h4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}