SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ec0aa2b6af0b4caa4b121509331f0364cf5b4c70d90975701865348336923ca' 
  AND token = '42wxACAzpWgjssVDNqJx0nvyZj9/0BNMOIqSzUHYcuQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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