SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30f5d16b6461d35540a9709d72cc5fa6f373caf8adaba7f4f2f0c1b2b5ec07e6' 
  AND token = 'qYS3qMdULT/qXI1JyOMLRKB83h0xSE79nIxHJqqKumI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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