SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1bf3ac639951785a5d862c629ec28485f91ca964dba3f1fd1878379daa41a770' 
  AND token = '7FpEJyxX0w+C39GjCOvmesby1ohwRGs1UMqiuG4LC4w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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