SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '313c9060118253c05e90cc754e9e90001ef191681dbcc030846e67fd327538e6' 
  AND token = 'vLFjdvVbe19I2wh6QvHixtS4doPkdRzgDdQ1jELUpwk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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