SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae3903dbd505be340204f4a8c69e50296e639da62a1fa320b1f85ebe764fbeff' 
  AND token = 'Cp/D4pvlD8JOQNOKbWHN0TGbcSVJhjbD/JaeIq/ynzE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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