SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c77bb6b3b716f6b839db758c914dabdcc9de7754274f3e25d808ddf3f2f550c' 
  AND token = 'cpXTXfcixWQpz3goZxVXnE8eyc/SW2GOnXDukfP76D8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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