SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '461228865dcef6d21de63bb43c679001bc00a78eb69e3fc8fc5f3164bda0e515' 
  AND token = 'xsJeLjtCLDt5+lhUgsGlS1OXwqGWSJ0kmhTdSDuwKYY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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