SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e95464883bb25fe739cf82a3f26552830754dca6fcf4a0e4815415b85cb26c31' 
  AND token = 's1FfzYSiLlGefiFMXcV52/nKbqOOO/uv5Il2nmP0y4o=' 
  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"
    }
  }
}