SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31bbc24dfec779562b020643b164183fbe5bc0bebc87778f29950d9d1e83a865' 
  AND token = '/ArPzrMw4hUClE4PSljtz8oWutbbcX3yQTZKeOll6s0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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