SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a191dbf9cf417b3d1e70a9c75f64c999968921bb36699c4b32f97d349fdf7aea' 
  AND token = 'SG8+wcO4PgghnKB+0SA3og+yp6Q4jSjh7JSk/UvhYTQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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