SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be9876dbc181268141539afe4a3b4aac8e399827cbc6986965f532969d95689d' 
  AND token = 'SKzzaUsvZuLTkPIy3saDecM6N/ir8NLiAACPV5/NVhQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}