SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a9bbc166b77026ff2f03d3cbeac3cb6d1f83b9ab58c065c0a9d6089ac853e02' 
  AND token = 'PCvnM6EfBdizLHL62lBH3JxjDjmSFEgtC4DYJjiHFUA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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