SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4b349e837632e307455c9641e4e297dd7fa722fb01a0a656986dc7fddcfd7b2' 
  AND token = 'Vpiou8Jo2CjghYYPJ+ifJ0/MavPIZJOlFJ79Few+UR0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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