SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e02e42ab0ee0dedf1053b4a5c74693d01d14a26242a5014c3e24db9698e94c6e' 
  AND token = '2Edgm/emAA1fXH6mhuqbLwLhoAyMxnxzR6wOyRNjIRg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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