SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa9601e01c2a3c1745b1463d72a111573833f21ac275639a716d5b6bfb40622e' 
  AND token = 'BVmY2UvchxRZAxCuMCVqurrfs/Fa7ldUSKe9Qk6WGsg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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