SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8c0ab8aadea40afc210f17655f8dbe117109292b5a048e560b3b64290b608dc' 
  AND token = 'iNtJTdKftGEhyAXY9pexULiXtZUIszKjpvKLQC1wyRs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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