SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f01a8fca636eb4a56e3eea42bfc8499fa2252c9547aecbdfe36f428300adc91' 
  AND token = 'l4+dcp6FsH/eAt1pWTrAKi65S9gAhhzo5X4WWRfD3ms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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