SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '108c94272c4c6732015697e433140aa38055f489bbce3cd76b90309d38c91424' 
  AND token = 'ivPTJpek4vNQK2CRlrFmvPxQVXfZtYCkzIqhXvwtSdg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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