SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bcbd29dc24540a2ae78d767417be5b786fb8ad49cfe6b6d140ce193a131fed27' 
  AND token = 'HvQmxEdq4tjVMJ1ZpctY0ozMhUIIy9MEV/fUJkX2Oyw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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