SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f134f5574abd2f27a618faaf3d9a3738b3a235674628f78c846d31d64684c28' 
  AND token = 'np4Xi7yC/YfIEUwWkcWuXB1Z+y8ww4XFJ4uBm2vHGQM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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