SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4eba93df3461ff4449d32e2d8f83905054d9fc4867b80a2b1e5168b784681624' 
  AND token = 'SfZn1FlgpwWxW7UUpMH/elYJoAQ6U+QVkabrEbnspBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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