SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a094c7f833fab1e13a0e3d93902549c5a760bf3530558acbf38007759a917699' 
  AND token = 'M6GHvoUGRfoxYb2zHvm0rrr2sM/y4iJDAqCxVebZTcU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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