SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '297435975b9359206af7c83165f5766b29b5e1edc161cbf6b56c495c1ccbb54a' 
  AND token = 'JRS/3HTMkpKTCt7CqZHiLPuKtYyikuvXZGXJW7MR6bA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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