SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e63f6183db5a7f9593cd59a08cf0c27465d1bdca675188a65f1f2420c608772b' 
  AND token = 'aiM+VgCrY+0SN+eoK0Tc9rGOj71vk6HKQ/o+fbQXRBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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