SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18f6f56c55bbce8e410237339b00a4f55ba8efbd738ca353c3a945ad7926c07a' 
  AND token = 'a94wMpqTaVQ45cmh6m6NIS3pJcbmWU2KeXNxBrJRDzQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}