SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05fc23394d138652ff63e62a42f7b0f043f482254d865c2923cdf3ed1994d5b9' 
  AND token = 'DfpwQbtEawN3NiU8XCQPrv+rO+RQuqgzRzOaLzzD17w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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