SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d02ec833d0ee0a26c41114c55922ff44ed96a5729c6e11beae75225da2ba3d8' 
  AND token = 'fyM/AiBAXkQGwUWySO6hl1mWbeN+rWBP7yWIu9sRR3k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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