SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11e76aadd8e0d91688168698b88dc6d0d73cd8681e73db309f22a07de6ffa23e' 
  AND token = 'pvppMD8bUeww5T9E7K/1bliTouvR4pxVfa3t2cNVflg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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