SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fee48d96c221db5db6438ec7c2c698846bdbd0645740bc5cb485e1eeaf19f158' 
  AND token = 'ne+8h3v0CU6fqLrOTyTZ4lP2F1nGyVrYt87Fqo9fado=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}