SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e099ae677682b5d3a6e5e521e8a1265fb221b6cce075472a8fee8e2067c8e13' 
  AND token = 'D9RnnQAtIQHuZImgv8qTaDFWrYthCte9k+Vg+HpbueE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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