SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d59fa22bcf7cd380f17b79c9277974a409980b368fa50eab405287a757a39a7' 
  AND token = 'y8lIDSfdaT8N/tRmv8Rde/GT9wQoKB2vUzzFpKDAl9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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