SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ecd116494c2fcf729743a6d5fe3a213984abbe0f86511cd49547c6b02feb448' 
  AND token = 'UF2K1JNzsibs5+nKrIEObGJcHHhLqFlrfudTy5A1ajw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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