SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '662de394c88b2948b811518328e7879f571d2f559d83da8d59463644685842cc' 
  AND token = '8IyN6mRakv5qjw0PTMFcGOFe1AvsLmfB451sQBj5Dps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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