SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f33f054c1f07670f9a2940e24569cd2bf03e096de508548c9174c3cfc21e137' 
  AND token = 'ukFRNuMhXkEEIlVtJ+M5Ok9J10lpr3TZDzsDhh27E4E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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