SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bdb7cb32cea26f0ca65f0d02e0247102b54e716b85cde8e220d00b4c56c4f5c' 
  AND token = 't5LXPZOrz1r0WscwYWPms9OWCSI91wFBUIhcbDklLQs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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