SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f95b001eb313540527bf668e7d90816787763c39a1551637e287ec9487f5a3ae' 
  AND token = 'hiUmdZQg1TA9Exdk9rlyky9QNgYSvXhkhzUM8cIecyw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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