SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c238d1aa0f5f26fe5b930bbf993bfc31ef74631cd6839b3487d5c12934aed5d' 
  AND token = 'bNAmDL6eFWHtTQYtl/YjN6CM58fZXt9TPMglU4MYw4Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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