SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e70fa7b546c552a14f94ee647c1c31a8dd1f4a09821b7822ea879936fb8d949' 
  AND token = 'JEe4fNJs5TYB/rCZ+TuF6JISxye9pzeS9Izoz1xPtDY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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