SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fdaf55ee6903cb12f46f9ee3182b9220acffb73efa5fd8cd0b3ac9762a9c9612' 
  AND token = 'IgBT1uB/lz/ORRPiQSJqmrOalm7xXtjKv7ZaH9rF5Ek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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