SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10aacdff08ef484d16eb1268305097e060271be47070b70c8d7ec3b65fbfa05f' 
  AND token = 'Ei36D+bSt60bLEJahL9tz1STwCPSc69dQpXZgGPqkQg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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