SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7132818b564fa84c75f250bddd45f9958d3a63c7041dad9df9206b352c54a943' 
  AND token = 'XVT+QfFpLc1ynJhjVmno2Wb24+xrHsg4Zlb2tEC5FiY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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