SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e95d23b2011ed88af490242856680252a1c1da302df77eb18464b941ef784993' 
  AND token = 'nXVxgDzR1BLqzwcGNvXRosn6p1hATl7inakJ/VBLWRM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}