SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '126874f643529e9c8faef5d6a6bb25fff2fd9e98114031eb6f47958105921d75' 
  AND token = 'Fhfyks27g2aRRsV8klniHhQpBwbySBEUEFF9auKsb80=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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