SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b2205b2467daf55ed37d63615826175d4f6eb04061e4924f82462821820d719' 
  AND token = 'rqc7gxTEpcPaLE8LEBcnD5DPRT3ZBdKokuz8jPGemx8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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