SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92c0d2da191ac46e89015a16fbaa65ed34c547b370852fbe22b1f3a601cd8440' 
  AND token = 'RVNH+yloYW3HKvaTD/YkgLgwFXA38chOKuBXjh75/cc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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