SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f19df9cb5f408e4354a7fe26fba1e75c36a058b186a11bc2b9a07410e25a973d' 
  AND token = '/GIUdyi6q6yj76ODdy2pNsozOB/wrDfhaXT5WEw7+og=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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