SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b10ba3666af7feb3e7644604cd43c5834db211ee03693044c003ea6715a89b82' 
  AND token = 'M5w2auAq1W8eRjHXXH3BOAtGrk3qduXBnIrQYF0O658=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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