SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f616e9ecc4fcdb2c78d50c976e55507be82e93a2b2d4550164c298198ccf2e6' 
  AND token = '5S/cGV/Sp6iz+AK0l2H2HEHuSp8MIY3l46tdRfwYdUI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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