SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71e1f906095f41a8ed389ef07bd304227628389c08e2c5e68ca6651bdbc68d7a' 
  AND token = 'bCHsm/K+pM+ubZK7rrHq4U7WVxNWGHVhppZtgB8enX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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