SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c969a32133f1141362e28b23dd47c94797dfcd3515a1df368bbe8cfb719c2bf3' 
  AND token = 'p9+R57AaRpFS1WLiICI/WGwsOuFS7418i3kv8MTyghs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00075

JSON explain

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