SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '336a8b3cc42d6dbb185ebe1c32a358f22459e07ad66ca15582f4caea368740dd' 
  AND token = 'vq9/TPFL1FYhp6b/YZXzAeXjZaigLlWtuUa5PJQLKBU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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