SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '198d81cfd76ac93da554b3ea3ee3e5529b15b1b4347a760f90748560dfc26e02' 
  AND token = 'K9VOn7mjqDGVlQzDNhj+bg0gG4+7iJii7CdfF+CYJuk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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