SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '362fb204997694bf6d40da640d769dbb0b3df2c3f1feae88a979adf958da422e' 
  AND token = 'XEs+bqpauaTptqJWCpOQjPsCYvhbtQVKT3uBv3QLIfA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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