SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7c86b3a41ab3ab072b08f770c49b0b2c340a281262d95c779dec7429ead434e5' 
  AND token = 'hre+apF8xmiieC8g/qEvBYgUcrawKqploA3vPYDuKU8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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