SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc56ea974a29ea7de346adf0a2852efc234eeceea0c95714635789771194318e' 
  AND token = 'uFnW1mnDWyv2ecThAQbgLIiPsE3JlYV/5Yw6IfRq9fE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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