SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0de2deb812de70481d780c294d26378536bbd492e689e58ab23e7a567408f3b2' 
  AND token = 'yaBcQYtVUSQ4xcEauQmIUfpYExCoSZaTeGW4MLatiwo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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