SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '057d567eedcc3b2ed7662035a77da940f228280288203da596e80e82ac70bff0' 
  AND token = 'bh85vM+9oQ2OLZNV5Xyb9mqDZ/LBYlym1apj9qniyk8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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