SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a042017abd80e35545b0cb89eee1127667ed9dc00d5717f765e1f94c63d89ee0' 
  AND token = 'wBWbdphkuDihsJDX7j2Pyd7UFVRwqM7FG43pali45kY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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