SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66219119f68edbb9b51924c6c0e58408087d657c454582ab7f46070d6f643ce9' 
  AND token = 'OxGdUCSP2rSeNbWOkjyQDy1+jyyTy2X5rdYlyOcXnN0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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