SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d53c820ce29623b7e34c9e42783468a5461096ef1c98cbd2563d57ea2ec88d0' 
  AND token = 'Y+NmR4ACdLw3wZgAlQhfh93kxxQWSDIY1TC88U/Vx1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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