SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bba46d8b7cddcf1265ff7959736c9ec0858398723c7c3bc2f41e84c1dfabbfaf' 
  AND token = 'kcqmTlkisJWN1YkmER2ryleGr/Ymj8H+LYl3yDgKQ7E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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